"Couldn't update to Windows 8.1 - 0xC1900101 - 0x40017"

I have been having the same issue. I recently updated my custom built computer, reformatted the raids, and installed windows 8 clean. after running windows update and checking for new drivers the system seems to be happy. however, when i run the windows 8.1 update i get the same error. After trying everything above several times the update still fails. At this point i decided to get Microsoft involved and contacted one of their techs. I gave him remote access and after running a couple scans he tells me the update is failing due to some kind of leftover corruption from the old windows 7 install and he knows what the issue is and can fix it but that type of support is only for their "premium users" which will cost me $100. he can not even point me at a specific problem or tell me how to fix it on my own without me paying for it. so i imagine many of the people who are still having issues after following all the steps listed in this thread are actually having the same issue as me. so just take comfort in the fact that Microsoft knows what the issue is and they will be glad to tell you as long as you pay them more money

hi 

i have asus ultra book pro and nothing extra is connected to laptop. (i7, 8 gb Ram )

i already installed 8.1 which worked fine then. 

now after i reinstalled windows 8 successfully and wished to upgrade to 8.1 i am getting same error message. 

i installed all necessary updates and additional option updates before going for 8.1 . but still problem persists. 

suggest

Hello to everyone on this post. After experiencing this error and scrolling through dozens of pages I finally found page 75 with members reporting success after removing Avast . Thank you to all.  It worked after removing Avast Internet security. Perhaps Avast need a big hint that they need to do something about their product.

I noticed quite a bit of Microsoft bashing in this post it goes to show that you shouldn't jump to conclusions before it has been worked on.

Sorry, I disagree with you.  Myself and many others do not use Avast and have not been able to upgrade to 8.1.  This has been going on for many months without any meaningful support or recognition of the problem from Microsoft.  I could go on about this but I'll simply say they deserve the criticism that has been voiced on this forum.

And I wouldn't be so quick to say Avast is to blame, they didn't develop the 8.1 upgrade.  I see it as Microsoft's responsibility to test their software and so state in their release notes a problem installing with other popular  products.  This they have not done to date that I know of.  They won't even acknowledge that an installation problem exists.

The real problem is not Avast.

I couldn't agree more with you. It beggars belief that Microsoft engineers haven't got to grips with this fundamental issue. Worryingly for the corporation's marketing types, many patient non-techy types like myself, loyal to Microsoft for many years,  are likely to give up the ghost with the whole Windows 8 fiasco and move to Apple.

Yes it finally works

During multiple failed updates i noticed an error flashing by after the first restart, to fast to read :-(

With a Lucky hit on the pauze button i managed to read it.

"not enough memory to create a ram drive"

My old pc only has only 2 Gb of ram, and i already disabled en uninstalled everything i could.

I also use the onboard videocard and this card uses a part of system ram.

I installed an old videocard and disabled the onboard videocard and the allocated memory in bios setup.

and now it works, hopefully i can help someone with this info.

Grts

Leo :-)